Step 1: Firstly, enable USB debugging mode of your device. To enable, Go to Settings » About Phone » Scroll down and tap build number several times until you will see a pop-up which states that, “You are now a developer”. Then go back to settings » developers option (which is above “About Phone”), and enable USB debugging. Also turn on “Advanced reboot option” and turn off “Cyanogen recovery”. And connect your device to PC.

Step 2: After that, boot your device to fastboot mode. To boot, simply Press and hold the Power button, then select and hold Reboot. You will get four options. Simply select “Fastboot Mode”.